bp2.vhd

在FPGA或CPLD上实现的一中非常实用的倍频电路

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;
entity bp2 is
port (clk : in std_logic;
   indata : in std_logic;
   indatb : in std_logic;
	    y : out std_logic);
end bp2;
ARCHITECTURE a of bp2 IS
	SIGNAL b : STD_LOGIC;
	SIGNAL c : STD_LOGIC;
	SIGNAL d : STD_LOGIC;
	SIGNAL e : STD_LOGIC;
	SIGNAL f : STD_LOGIC;
	SIGNAL g : STD_LOGIC;
BEGIN
	Process (clk)
	begin
	if clk 'event and clk='1' then
	b<=indata;
	end if;
	if clk 'event and clk='1' then
	c<=b;
	end if;
	end process;
	Process (clk)
	begin
	if clk 'event and clk='1' then
	d<=indatb;
	end if;
	if clk 'event and clk='1' then
	e<=d;
	end if;
	end process;
	f<=b xor c;
	g<=d xor e;
	y<=f or g;
END a;